﻿Shader "UI/ImageRoundCorner"
{
	Properties
	{
		[PerRendererData] _MainTex("Sprite Texture",2D) = "White"{}
		_Color("Tint",Color) = (1,1,1,1)

		_StencilCopm("Stencil Comparison",Float) = 8
		_Stencil("Stencil ID",Float) = 0
		_StencilOp("Stencil Operation",Float) = 0
		_StencilWriteMask("Stencil Write Mask",Float) = 255
		_StencilReadMask("Stencil Read Mask",Float) = 255

		_ColorMask("Color Mask",Float) = 15

		[Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alpha Clip",Float) = 0

		_RoundedRadius("Round Radius",Range(0,256)) = 64
	}
		SubShader
		{
			Tags
		{
			"Queue" = "Transparent"
			"IgnoreProjector" = "True"
			"RenderType" = "Transparent"
			"PreviewType" = "Plane"
			"CanUseSpriteAtlas" = "True"
		}

			Stencil
		{
			Ref[_Stencil]
			Comp[_StencilComp]
			Pass[_StencilOp]
			ReadMask[_StencilReadMask]
			WriteMask[_StencilWriteMask]
		}

		Cull Off
		Lighting Off
		ZWrite Off
		ZTest[unity_GUIZTestMode]
		Blend SrcAlpha OneMinusSrcAlpha
		ColorMask[_ColorMask]

		Pass
	{
		CGPROGRAM

#pragma vertex vert
#pragma fragment frag

#include "UnityCG.cginc"
#include "UnityUI.cginc"

#pragma multi_compile __ UNITY_UI_ALPHACLIP

		struct appdata_t
		{
			float4 vertex : POSITION;
			float4 color : COLOR;
			float2 texcoord : TEXCOORD0;
		};

	struct v2f
	{
		float4 vertex : SV_POSITION;
		fixed4 color : COLOR;
		half2 texcoord : TEXCOORD0;
		float4 worldPosition : TEXCOORD1;
	};

	fixed4 _Color;
	fixed4 _TextureSampleAdd;
	float4 _ClipRect;

	float _RoundedRadius;

	float4 _MainTex_TexelSize;

	v2f vert(appdata_t IN)
	{
		v2f OUT;
		OUT.worldPosition = IN.vertex;
		OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

		OUT.texcoord = IN.texcoord;

#ifdef UNITY_HALF_TEXEL_OFFSET
		OUT.vertex.xy += (_ScreenParams.zw - 1.0)*float2(-1,1);
#endif

		OUT.color = IN.color * _Color;
		return OUT;
	}

	sampler2D _MainTex;

	fixed4 frag(v2f IN) : SV_Target
	{
		half4 color = (tex2D(_MainTex,IN.texcoord) + _TextureSampleAdd) * IN.color;
		color.a *= UnityGet2DClipping(IN.worldPosition.xy,_ClipRect);

#ifdef UNITY_UI_ALPHACLIP
		clip(color.a - 0.001);
#endif

		float width = _MainTex_TexelSize.z;
		float height = _MainTex_TexelSize.w;

		float x = IN.texcoord.x*width;
		float y = IN.texcoord.y*height;

		float r = _RoundedRadius;

		//左下角
		if (x < r && y < r)
		{
			if ((x - r)*(x-r) + (y - r)*(y - r) > r*r)
			{
				color.a = 0;
			}
		}

		//左上角
		if (x<r && y>(height - r))
		{
			if ((x - r) * (x - r) + (y - (height - r))*(y - (height - r)) > r*r)
			{
				color.a = 0;
			}
		}

		//右下角
		if (x > (width - r) && y < r)
		{
			if ((x - (width - r))*(x - (width - r)) + (y - r)*(y - r) > r*r)
			{
				color.a = 0;
			}
		}

		//右上角
		if (x > (width - r) && y > (height - r))
		{
			if ((x - (width - r))*(x - (width - r)) + (y - (height - r))*(y - (height - r)) > r*r)
			{
				color.a = 0;
			}
		}
		return color;
	}
		ENDCG
		}
		}
}